This invention relates to identifying the manufacturer of a sheet of gypsum wallboard after it has been embodied in a wall or ceiling and even if the wall or ceiling has been painted.
Presently, when a wallboard manufacturer's representative inspects a finished painted wall, in response to a complaint from a customer, there is usually no way to determine the identification of the manufacturer of the wallboard other than by removing the wallboard from the wall to read the marking on the back side of the wallboard. If the wallboard is clearly defective, but not unusable, it would be advantageous if the manufacturer's representative could identify the manufacturer of the wallboard and when appropriate make a cash settlement for the defective product rather than risk a substantially greater expense of removing the wallboard and replacing it with new wallboard.